The invention relates to an apparatus for distributing concrete, especially in shuttering of gallery linings in mine and tunnel workings with the aid of a travelling or transportable distribution mast carrying an articulated conduit for carrying concrete. The mast is pivoted on a column which can rotate around its axis and which is divided into several mast sections joined together by power-operated pivotal joints so as to be articulatable in a swivel plane containing the column axis. Thus, a swivel extension forming the end section of the mast can fold from above onto a main boom which connects the column to the swivel extension.
In mining and tunnel workings, a concrete lining is often applied directly to the rock. The shuttering or cover required for this extends longitudinally of the gallery and often comprises a transportable framework which is called a "shuttering cart". Logically the longest possible shuttering length is desired. By this, on the one hand, the number of transfer operations of the shuttering cart are reduced, and on the other hand, the total length of the end shuttering, which prevents extrusion of concrete at the front end of the shuttering, is shortened.
In the longitudinal direction of the gallery and in the peripheral direction, the shuttering of this kind should feature several closable filler openings in order that the shuttered-off mould cavity may be filled in an even manner, beginning at both ends and finally, in the roof area. Thus, in the case of large cross-section galleries, one-sided loading of the shuttering and the shuttering cart are avoided. However, with such an arrangement the nozzle of the concrete conduit must be attached and detached many times, and, because of the differing positions of the filler openings, considerable movement of the concrete conduit has to take place between these procedures. The amounts of concrete to be filled in each position of the concrete conduit differ but are, however, relatively small. On the other hand, large diameter conduits are often necessary, especially when large granular rubble occurring during the workings is used as an addition to the concrete.
An apparatus of the kind described in the introduction serves to facilitate and expedite the work procedures which are necessary to fill the mould cavity of the described shuttering. In known apparatus of this kind, the mast carrying the concrete conduit has two arms. One of the arms is hinged to the column, and the second arm is attached to the first arm by means of a universal joint and forms the swivel extension. The mast forms a special superstructure for a lorry which also features a concrete pump and a filling hopper to which the concrete may be delivered by travelling mixers.
Gallery heights have been for some time at a maximum of 12-14 meters, so that a relatively long mast is necessary. However, since the total length of the known masts is only divided into two mast sections, the rotational movability of the mast sections can only be exploited to a limited degree.
For this reason, the shuttering, with the known apparatus, must be filled from the end side. With the desirable long shutterings, the filling procedure demands the moving of the vehicle which must thus be provided with heavy suspended rollers on its swivelable supports as well as a disproportionately large filling hopper for a supply of concrete during the time of travelling when topping-up by the travelling mixers is not possible. The mode of operation, which is possible with such apparatus, is disadvantageous because the concrete conduit must be manipulated below the unlined, or only provisionally secured rock. The vehicle is unusually heavy and technically complicated.
For a long time, lorries with special superstructures for the distribution of concrete have been employed for construction and excavation workings. One of the distribution masts developed for this has a main boom divided into two mast sections. The power-operated joint between the two sections has a range of pivotal movement which, at least, permits positioning of the mast sections to extend upwards and forwards (German Auslegeschrift No. 2,000,382). The two mast sections forming the main boom are so arranged that the swivel extension can be folded between these two mast sections. For this reason, the two mast sections have approximately the same length as the swivel extension, and the power-operated joint connecting the two sections lies in front of the end of the swivel extension in the collapsed condition of the mast.
A distribution mast of this kind is not suitable for spatially restricted conditions which are encountered in mine and tunnel workings, because the unfolding of the mast with the required length of mast demands too great a height. Thus, its power operated joints can not be controlled so that under such restricted conditions as in mines and tunnels, the vehicle can not remain stationary between successive filling operations.
Because of such difficulties with the employment of distribution masts intended for construction and excavation work, devices have become known, in construction and excavation work for the distribution of concrete (Austrian patent specification No. 251022) in which the concrete conveyor conduit is laid on several rail vehicles and features a telescopic end piece which can be connected to branch pads on the shuttering. These known devices however, do not usually function particularly well because the extension pieces at the end of the concrete conduit become restricted because of the encrustations of cement forming there, and must be cleaned frequently. Besides such devices take up a lot of room which is urgently needed in driving galleries.
The object of the invention is to provide apparatus for the distribution of concrete with a distribution mast, so that the mast, which is folded in the transporting position as stated in the introduction, can be unfolded to a required length under restricted conditions, such as are encountered in mining and tunnel workings, so that by controlling the power-operated joints with the mast stationary, the end piece of the concrete conveyor conduit can be brought into a plurality of positions in which it can be connected in succession to the filler branches of the shuttering.